Calibration curve

About: Calibration curve is a research topic. Over the lifetime, 6552 publications have been published within this topic receiving 95128 citations.

Calibration of print contrast using an optical-electronic sensor

Abstract: The present invention is embodied in a system and method for automatically calibrating the print contrast of an inkjet printing system using an optical-electronic sensor to detect an ink drop volume The print contrast calibration system includes an optical-electronic sensor that obtains test pattern data from a printed test pattern, a calibration module that contains calibration data for the printing system, an installation module that determines a drop volume score by using the test pattern data and the calibration data and a printing module that determines a print contrast setting based on the drop volume score The present invention also includes a method for calibrating print contrast in a printing system by storing standard calibration curves for the printing system, comparing the standard calibration curves with a printhead assembly calibration curve to determine a drop volume score, and setting the print contrast based on the drop volume score

Method and apparatus for imaging porous media and method for fabricating novel optical materials

Abstract: A method and apparatus is described for determining petrophysical properties of porous media by the use of light transmission through the media. Specifically, by using a highly collimated light source, preferably a laser, the permeability, grain size, wettability, porosity and clay swelling behavior of a sample can be determined on the scale of millimeters. A calibration curve or function is first established to correlate light transmission through a slab of sandstone on the order of 5 to 10 mm under known conditions. This curved is then used to determine unknown conditions by measuring light transmission and comparing the values to those on the curve. Other applications for the phenomenon of light transmission through porous media are disclosed whereby conditions in a flowing stream of liquid can be monitored by use of light transmission. Specifically, changes in the refractive index and immiscible contamination can be detected. Finally, the phenomenon described can be used to model subterranean hydrocarbon bearing reservoirs, particularly fluid flow at different points in the reservoir, using light rather than hydraulic flows to simulate fluid flow patterns.

Determination of trace amounts of beryllium in water by solid-phase spectrophotometry

Abstract: A method for the determination of trace amounts of beryllium has been developed, based on solid-phase spectrophotometry. Beryllium reacts with Eriochrome Cyanine R in the presence of ethylenediaminetetraacetic acid to give a highly absorbent complex, which is fixed on a dextran-type anion-exchange gel. The absorbance of the gel, at 580 and 750 nm, packed in a 1 mm cell, is measured directly. The calibration graph is linear over the concentration range 0.1–1.2 µg l–1 and the relative standard deviation is 2.3%. The detection limit of the 1000 ml sample method is 6 ng l–1 for 0.030 g of anion-exchange gel. The sensitivity can be enhanced by increasing the sample volume. The method has been applied to the determination of beryllium in tap and natural waters.

Calibration of a mass spectrometer

Abstract: Apparatus and method are provided for calibrating a mass spectrometer. The calibration hardware includes a relatively small, relatively low pressurized tank for containing calibration gas. The calibration gas tank is preferably located inside the same housing that contains the ion source assembly and the analyzing section of the mass spectrometer. Each of the calibration gas and sample gas, whose components are to be determined, communicates with its own associated valve. These two valves control the flow of a selected one of the sample gas and the calibration gas to the ion source assembly. The calibration gas valve has an extremely low leakage rate and can be controlled to permit the passage of very low flow rates of calibration gas, which can be of benefit in checking the linearity associated with the ion source assembly pressure. For each calibration procedure, very small amounts of calibration gas are utilized, in a range around 10-5 STD cc. A related method for conditioning an electron multiplier device is also disclosed in which the gain of one or more selected channels thereof is modified so that the output signal strengths of the device are comparable in magnitude. Calibration of the mass spectrometer occurs frequently and automatically. In one emobodiment, the mass spectrometer calibration is a direct function of each mass spectrometer measurement. Consequently, improved accuracy and heightened sensitivity are achieved in the mass spectrometer, while reducing the use or loss of valuable calibration gas.